the u.s.edly spend $70,000 on these ads. >> since our founding, the united states has been a nation that respects all faiths. we reject all efforts to denigrate the religious beliefs of others. >> pelley: the embassy ad is running on seven pakistani tv channels, and here is why that ad campaign seems like a good buy. in islamabad today, more than 1,000 students, armed with sticks and stones, tried to reach the u.s. embassy. they were stopped by riot police and army troops who used tear gas to break up the crowd. the first reports from libya last week said it was a similar protest that ended in the murders of the u.s. ambassador and three other americans there. but today, for the first time, the white house called the assault on the u.s. consulate in benghazi a terrorist attack. elizabeth palmer has been investigating in benghazi. >> reporter: at a solemn memorial service, libya's president paid his respects to ambassador christopher stevens. u.s. deputy secretary of state william bornes had earlier flown into the capital under tight security. behind the scenes, an f.b.i. team is preparin